NULLPOINTER EXCEPTION when reading config.properties

Question

I am getting File not found when reading config.properties. config.properties is rightly there under com/wu/resources. What could be the issue?

Properties prop = new Properties();

InputStream input;
input = Readproperties.class.getClassLoader().getResourceAsStream("/com/wu/resources/config.properties");
if (input != null) {
  prop.load(input); }
else {
  System.out.println("file not found");
}

try input = Readproperties.class.getClassLoader().getResourceAsStream("config.properties"); — Nick Isaacs, Feb 19 '16 at 11:24
Drop the leading `/` - you're calling `ClassLoader.getResourceAsStream()`, not `Class.getResourceAsStream()`. — Jon Skeet, Feb 19 '16 at 11:26
@wero - /com/wu/resources is under src ...is there a way to attach screenshot here? — Panayappan Swaminathan, Feb 19 '16 at 11:27
@Nick - Read.properties and config.properties are in different packages,so putting direct value of config.properties also doesnt work — Panayappan Swaminathan, Feb 19 '16 at 11:28
Possible duplicate of [NullPointerException when reading a properties file in Java](http://stackoverflow.com/questions/3139532/nullpointerexception-when-reading-a-properties-file-in-java) — Harshad, Feb 19 '16 at 11:30
Okay, then you will have to provide relative path and not absolute path — Nick Isaacs, Feb 19 '16 at 11:30
@PanayappanSwaminathan did you put it in `src/main/resources` or just in `src` ? — rve, Feb 19 '16 at 12:09
@JonSkeet - Thanks, after removing / , it worked. How does this / makes difference between Class and Class loader — Panayappan Swaminathan, Feb 19 '16 at 12:24
In `Class.getResourceAsStream`, "/" is used to "root" the resource name, because otherwise it will be treated as relative to the class. That's not the case for `ClassLoader`, because there's no class for it to be relative to. See the docs for more details. — Jon Skeet, Feb 19 '16 at 12:37

Nikita Mittal · Answer 1 · 2016-02-19T12:20:30.470

It seems ClassLoader.getResourceAsStream(String name) returns null, which then causes Properties.load to throw NullPointerException.

URL getResource(String name): Finds the resource with the given name. A resource is some data (images, audio, text, etc) that can be accessed by class code in a way that is independent of the location of the code. The name of a resource is a '/'-separated path name that identifies the resource.

Returns : A URL object for reading the resource, or null if:

the resource could not be found, or
the invoker doesn't have adequate privileges to get the resource.

score 0 · Answer 2 · answered Feb 19 '16 at 12:16

0

try

input = Readproperties.class.getClassLoader().getResourceAsStream("src/com/wu/resources/config.properties");

answered Feb 19 '16 at 12:16

Raphael Roth

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NULLPOINTER EXCEPTION when reading config.properties

2 Answers2